1. Field of the Invention
The present invention relates to the recycling of hairs, and in particular relates to a method for manufacturing a protein filling agent utilizing animal hairs.
2. Description of the Related Art
Generally, the hair-saving and hair-destroying dehairing processes are carried out in leather industry. However, the wastewater containing sulfur of leather industry is mainly produced from hair-destroying dehairing process, wherein the COD content is more than 10000 mg/L which accounts for 40% of total COD in wastewater, and the sulfur contain is more than 5500 mg/L which accounts for 90% of total sulfur in wastewater. Thus, the hair-destroying dehairing process should be replaced with hair-saving dehairing process to solve the problems of industrial pollution. However, vast cut hairs would be produced in hair-saving dehairing process. The treatment of unnecessary hairs would increase the manufacturing costs so that the hair-saving dehairing process cannot be popularly used. Therefore, it is important for utilizing the waste hairs from hair-saving dehairing process.
Event thought the proposition of hair-saving dehairing process still is small in leather industry, it is more and more significant. The reasons include: 1. Environmental protection awareness of human is on the increase and environmental protection laws and regulations of countries is more stringent, so that the replacement of hair-destroying dehairing process with hair-saving dehairing process is imperative. 2. In contrast to hair-destroying dehairing process, the hair-saving dehairing process can significantly decrease the cost of wastewater treatment. If the problem of waste hairs can be solved, the cut hairs obtained from hair-saving dehairing process would produce a huge economic benefit. Thus, a novel method to reusing waste hair is needed in leather industry.
Currently, recycling of hairs is utilized for wool and pig hairs. Wool can be made a carpet and has a superior spinnability. However, because the ability for wool to be spun is hindered after being recycled, the cut wool only be made a carpet or discarded. Pig hair has a superior hardness and breaking strength so that pig hair can be made a brush. However, for pig hairs, because characteristics for pig hairs like hardness and strength, after being recycled is decreased, the efficient methods and manufacturing of the cattle hairs have yet to be disclosed. Thus, the hair-saving dehairing process is desired, wherein hair may be feasibly recycled and utilized without increasing pollutants.